# Demographics → ERS Index (ers_index)

| Variable | ERS (Z only) | ERS (Z+ctrl) | ERS (Z+ctrl+int) |
|:---|---:|---:|---:|
| Z_1 | 0.0284 | 0.6348* | 0.6975* |
| | (0.2806) | (0.3783) | (0.3931) |
| Z_2 | 0.0091 | -0.0694 | -0.0770 |
| | (0.0442) | (0.0577) | (0.0610) |
| Z_3 | -0.0006 | 0.0020 | 0.0022 |
| | (0.0019) | (0.0024) | (0.0026) |
| fiscal_bal_gdp | | -0.0000 | -0.0001 |
| | | (0.0009) | (0.0009) |
| nfa_gdp_lag | | -0.0024 | -0.0033 |
| | | (0.0068) | (0.0068) |
| rgdp_growth | | 0.0007 | 0.0007 |
| | | (0.0005) | (0.0005) |
| log_rel_opw | | 0.0107 | 0.0105 |
| | | (0.0142) | (0.0143) |
| kaopen | | 0.0402*** | 0.0482*** |
| | | (0.0060) | (0.0097) |
| Z_1_x_kaopen | | | 0.1866 |
| | | | (0.2213) |
| Z_2_x_kaopen | | | -0.0246 |
| | | | (0.0342) |
| Z_3_x_kaopen | | | 0.0009 |
| | | | (0.0014) |
|:---|---:|---:|---:|
| N | 9836 | 4482 | 4482 |
| R² | -0.0153 | 0.0611 | 0.0635 |
| Countries | 160 | 148 | 148 |

*Standard errors in parentheses.*
*\*p<0.1, \*\*p<0.05, \*\*\*p<0.01*